Why Your Hearing Has a Built-In Fear Response

They all have unforgettable soundtracks that bring about an instant sensation of terror. Indeed, if you view the films without any sound, they become a great deal less frightening.

But what is it regarding the music that makes it terrifying? More specifically, if sounds are simply vibrations in the air, what is it about our biology that causes us to react with fear?

The Fear Response

In regard to evolutionary biology, there’s an obvious survival advantage to the automatic identification of a deadly situation.

Thinking is time consuming, especially when you’re staring a ravenous lion in the face. When every second counts, you don’t have the time to stop and process the information consciously.

Seeing that it takes additional time to process and contemplate visual information, the animal brain is wired to react to quicker sound-processing mechanisms—a characteristic that offers survival advantage and has been selected for in the wild.

And that’s precisely what we discover in nature: numerous vertebrates—humans included—produce and respond to harsh, nonlinear sounds and vocalizations when frightened. This creates a nearly instantaneous feeling of fear or anxiety.

But what is it about nonlinear sound that makes it scary?

When an animal screams, it creates a scratchy, irregular sound that stretches the capacity of the vocal cords beyond their typical range.

Our brains have evolved to distinguish the attributes of nonlinear sound as abnormal and indicative of life-threatening circumstances.

The interesting thing is, we can artificially mimic a wide array of these nonlinear sounds to bring about the same instant fear response in humans.

And so, what was once a successful biological adaptation in nature has now been co-opted by the movie industry to produce scarier movies.

Music and Fear

We all know the shower scene from the classic movie Psycho, and it’s certainly one of the most terrifying scenes in the history of cinema.

But if you watch the scene without sound, it loses the majority of its affect. It’s only once you incorporate back in the high-pitched screeching and bone-chilling staccato music that the fear response becomes thoroughly engaged.

To reveal our instinctive aversion to this nonlinear sound, UCLA evolutionary biologist Daniel Blumstein carried out a study assessing the emotional responses to two types of music.

Participants in the study listened to a selection of emotionally neutral scores and scores that incorporated nonlinear elements.

As anticipated, the music with nonlinear characteristics aroused the most powerful emotional responses and negative feelings. This response is simply a part of our anatomy and physiology.

Regardless of whether Hollywood comprehends this physiology or not, it knows instinctively that the use of nonlinear discordant sound is still the best way to get a rise out of the viewers.